The hypothalamus controls excretions from the pituitary gland. It causes the release of some hormones from the pituitary by direct nervous control, and others by secreting releasing and inhibiting factors that stimulate the pituitary to secrete hormones. Which best describes the hypothalamus?

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.